PURPOSE: To perform a retrospective evaluation of a new treatment for obstructive meibomian gland dysfunction (O-MGD) using invasive orifice penetration and intraductal probing.SETTING: Office-based ophthalmology private practice.METHODS: Medical charts of 25 consecutive patients with O-MGD (based on presence of lid margin or tarsal hyperemia, lid margin telangiectasia, thickening or irregularity, and meiboman gland orifice metaplasia) plus lid tenderness or symptoms of lid margin congestion were reviewed to evaluate the effect of probing on tenderness and congestion.RESULTS: Twenty-four of 25 patients (96%) had immediate postprobing relief, whereas all 25 patients (100%) had relief of symptoms by 4 weeks after procedure. Twenty patients (80%) only required 1 reatment and had an average of 11.5-month follow-up. Five patients (20%) had retreatment at an average of 4.6 months. All patients had symptom relief at time of last follow-up. Of 56 symptomatic and treated lids, 42 (75%) were upper lids. Patients frequently reported improvement in newly recognized but previously subclinical symptoms.CONCLUSIONS: Invasive orifice penetration and intraductal probing seems to provide lasting rapid symptom relief for patients with O-MGD. Probing findings in this study frequently included (1) mild resistance upon orifice penetration, (2) proximal duct gritty tactile and aural sensation suggestive of keratinized cellular debris, and (3) focal variable resistance deeper within the duct, which may be relieved with the probe, suggestive of fibrovascular tissue. Taken together, these findings may offer probing characteristics that may allow for a grading system for duct obstruction. The postprobing improvement of symptoms not previously appreciated supports the notion that meibomian gland disease exists subclinically.